These holes let water slowly pass through the walls of the filter.
VOA: special.2009.06.22
Tests have shown that the filter produces safe drinking water.
VOA: special.2009.06.22
The original design of the ceramic filter came from a chemist in Guatemala,Fernando Mazariegos.
VOA: special.2009.06.22
The water filter costs little to make.
VOA: special.2009.06.22
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